The invention generally relates to the field of precision cam assemblies and more particularly relates to the field of the use of such assemblies for controlling the selection of different track positions for a magnetic tape head in a magnetic tape player/recorder.
Prior art cam assemblies generally comprise a cam member having cam surfaces, a cam follower which is mechanically coupled to the cam member and an apparatus for providing relative movement of the cam member with respect to the cam follower. Relative movement of the cam member causes different portions of the cam surfaces to contact the cam follower and produce corresponding movement of the cam follower. Whenever precise movement of the cam follower is required, such as when the cam follower movement controls the track (height) position of a magnetic tape head in a tape player, various cam surfaces must be provided which bear a precise relationship to each other. Generally, prior art cam assemblies have used a unitary cam member which has a plurality of cam surfaces on it, all of which bear a precise dimensional relationship with respect to each other. These precision cam members have therefore been relatively expensive due to the exact tolerances which must be maintained for their manufacture. U.S. Pat. No. 3,624,309, which is by the same inventor and assigned to the same assignee as the present invention, illustrates the use of such a prior art cam assembly to control the track position of a magnetic tape head.